Electron discharge device



p 1933- M. MORRISON 1,925,107

ELECTRON DISCHARGE DEVICE Filed May 19, 1930 2 Sheets-Sheet l I vzvenior Sept. 5, 1933.

M. MORRISON 31,925,107

ELECTRON DISCHARGE DEVICE Filed May 19, 1930 2 Sheets-Sheet 2 F1 :9 w Q 1 E I W rm Pm/WWW Patented Sept. 5, 1933 UNITED STATES PATENT OFFICE 10 Claims.

This invention relates to a class of thermionic discharge devices employing cathodes, anodes and control grids, and may be embodied in any of the general class of electron devices, which includes thermionic rectifiers, radio tubes, mercury arc rectifiers, and other similarly operating devices.

This application is related to co-pending application Serial Number 421,790 filed January 18, 1930 and Serial Number 449,216 filed May 2, 1930.

Among the objects of this invention are; to provide for electron devices employing rotating electric fields, electrode structure and arrangement better adapted to practical application than those disclosed in the above cited co-pending applications; and to provide additional means of obtaining advantageous and desirably tube constants for the embodiments of the above cited and already disclosed inventions. Further and other objects will appear to those skilled in the art to which this invention appertains in the specification and claims hereunder.

In the disclosed inventions above cited, certain practical considerations including tube constants involving such features as high spacecharge effects were omitted for clearness in teaching the broad aspect of the inventions; and. in this application some of the more practical novelties useful in the embodiment of the invention are disclosed.

In the accompanying drawings, Figs. 1 to 4 inclusive are representations of vector-fields used in connection with the specification hereunder; Figs. 5 to 7 inclusive are conventional illustrations of electric fields associated with the elec trodes used in an embodiment of this invention; and Fig. 8 is a diagram of connections, illustrating a use of the invention as claimed hereunder.

The general and detailed physical structure of an electron discharge device of the class described herein, has been described in full and clear detail, such as to enable one skilled in the art to make and use this invention, in the two above cited patent applications; and in view thereof, the present application will be concerned principally with those novelties of construction, aside from that already described in the two mentioned applications, as will give those skilled in the art a clear specification for making and using the invention.

The mountings, supports, materials and processes used in the described embodiment of this invention may be similar to those described in the references already mentioned.

The utilization of revolving electric fields in electron discharge devices may be understood from a consideration of the following expressions relating to vector-fields employed in the described embodiment.

Using a pair of rectangular geometrical axes; and upon one of this set'of axes, consider the projection of the expression cos (1) 1 F sin n and on the other axis, the projection of n )sm (2) for which the origin for the polar coordinates thereof is at the intersection of the two axes.

By expansion and transformation of the above expressions, there can be made to appear in the expressions, terms of mathematical character equivalent to sin (4) and cos (5) and the vector sum thereof is and the vector therefor revolves about an axis at the intersection of the two assumed axes with a period of 211'.

These mathematical expressions have two important and difierent interpretations in the embodiment of the present invention.

Referring to (2) the sine terms thereof may be looked upon as an expression for a sinusoidally varying electric field of uniforni distribution in and about the region considered; and the cosine terms thereof may be looked upon as determining the vector direction of the aforesaid field (projections) Referring to (2), the first sine terms thereof may be looked upon as representing sinusoidally varying electric fields, and the second sine terms thereof, the vector directions of these said fields (projections) Before going into the interpretation of these expressions as related to the figures, a very simple case aside from the equations, and more easily understood, will be discussed, as an introduction to the physical basis of the theory involved.

Referring to Fig. 1, consider a uniform electric field having a direction represented by the vertical arrows in this figure and a. magnitude varying in accordance with a sine function. Also consider a second uniformly distributed electric field at right angles thereto. represented by the horizontal arrows in Fig. 1, and varying in accordance with a cosine function corresponding with the aforesaid sine function and of equal amplitude.

The combined effect of these two fields, or mathematically speaking, the vector sum thereof, in and about the center of the field may be represented by the diagonal arrow, the direction and magnitude of which is determined by the so-called parallelogram law, which, as related to the present case utilizing rectangular combination, is represented by of the sine and cosine functions in which r epresents the angular values as well as the vector directions of the resultant field, which is constant in magnitude and revolves about an axis with a period of 21'.

In other words, two superimposed electric fields of equal amplitude varying sinusoidally, and differing in phase and in angular direction by 90, results in a revolving field of constant magnitude.

Generally speaking, the revolving field would have somewhat the distribution and direction indicated by the arrows in Fig. 2.

Another physical interpretation of the same general trigonometric representation may be considered as follows:

Referring to .Fig. 5, consider the arrows representing the amplitudes of the sinusoids illustrated therein, as representing the direction and magnitudes of two superimposed electric fields. The fields are distributed non-uniformly in this case and individually the distribution is stationary; and the two fields vary simusoidally, having instantaneous values of an angular magnitude equal to the graphical phase difference in the said waves. The instantaneous amplitude of one sinusoid varies as the sine of an angle having numerical values reckoned from time, and the second sinusoid has instantaneous values varying with the cosine of the same angle.

The algebraic sum of these two distributed fields is a third sinusoid of constant amplitude, and moving in a direction parallel to the axis of the first two sinusoids as illustrated in Fig. 6.

Mathematically, the value of an ordinate of one of the sinusoids of Fig. 5 is proportional to the sine of the angular value in radians along the axis of the ordinate, due to the distribution of the field; and further proportional to the sine of the same angle, due to the simultaneous sinusoidal variation of the field, making the combined value proportional to the sin of the angle. Likewise, the other sinusoid will have ordinates proportional to the cos, the sum of the two being represented by sin sin +cos cos (7) which is equal to (6) The field represented by (6) revolves with a period of 2, and the field represented by (7) traverses the same angular distance in radians, in an equal time. The curve in Fig. 6 moves bodily along the axis thereof without changing in form or amplitude.

In other words, electric fields of constant amplitude, but moving in direction, may be obtained with equal quarter phase uniform fields at right angles, or with equal quarter phase fields having sinusoidal distribution.

Expressions 1 to 5 inclusive represent a more general aspect of these phenomena.

In one specific case involving these equations, a higher number of fields will be discussed.

Assume the case of three equi-spaced fields varying sinusoidally. Expressions 1 and 2 reduce to F sin 5+ cos 2 (8) m=l and F sin 3 sin 3 (9) in Fig. 3, resulting in a uniformly distributed i electric field of constant magnitude, and revolving about the center thereof, as illustrated in Fig. 4, and with a period of 21.

These expressions may be further interpreted as representing three equi-spaced, three-phase sinusoidally distributed electric fields parallel to one another, and each varying sinusoidally in phase relation to the space separation thereof in radians, as illustrated in Fig.. '7, resulting in an electric field of sinusoidal distribution and of constant magnitude, moving in a direction parallel to the axis of the sinusoids as illustrated in Fig. 6.

Such fields as described in Figs. 1 to 4 inclusive, have been clearly discussed in the above cited co-pending applications; and one of the objects of the present invention is to teach those skilled in the art to make and use electron devices, embodying the invention described in the above cited references, utilizing fields of the character illustrated in Figs. 5 to '7 inclusive.

Referring to Fig. 5, consider 1 as a thermionic filament, and 2 as an anode, both enclosed in a suitable vacuum device together with the grids hereinafter described. The circles 3 represent derstood further on in this specification. The conductors connecting the circles together form no part of the grid structure within the active field thereof, but merely represent connecting bars at the top and bottom of the grids.

The grids in this invention are distributed with respect to the filament and to themselves, taking into consideration all factors essential, including wire size, and other important factors, such that the electric field distribution between any grid such as 5 and the filament 1 will be sinusoidal, as illustrated in the figure and somewhat after the fashion employed in electric motors to obtain sinusoidal magnetic field distribution under the pole faces.

Quite obviously, the form of the filament as well as that of the plate may be brought to bear to influence this distribution, if and when desired.

In Fig. 5 there is illustrated in an exaggerated form such a grid distribution as would be required to produce the electric fields illustrated thereunder.

As heretofore pointed out, the mechanical structure required to form and support such a grid, has been fully disclosed in the two above cited co-pending patent applications; and only the novelties individual to this invention will be described in detail.

The practical embodiment of such a grid structure as illustrated in Fig. 5, is conventionally laid out in Fig. 8, in which like parts have like numerals.

Fig. 8, 1 represents the filament and the grids 4, 5, 6 and 7 being shown in a circular form as is advantageous in a practical device. Parts 7-A and 7-3 of Fig. 5 forming one grid in Fig. 8. The plate 2 surrounds the grid structure; and the whole is enclosed in an hermetically sealed, properly-pumped-out envelope 8.

The filament 1 has a plurality of loops 9, which are fixed to a plurality of supports 10, held by a press 11. This loop structure 9 serves as a means for removing the cooled section of the filament 12, adjacent the support from within the highly active electric field, eliminating a region in the neighborhood of 13, being devoid of electron emission.

The electric field illustrated about the filament 1 in Fig. 5, has now the curvature of filament in Fig. 8, and is continuous, so that the moving field described in connection with Fig. 5, and illustrated in Fig. 6 moves in a direction parallel to that of the filament, and about the center 14 of the tube in Fig. 8, so that with the application of suitable currents to the grids already described, and which currents will be more fully hereinafter discussed, the electric field distribution between the filament and the grid, with respect to its control of the plate current, is uniform in distribution and constant in magnitude, but revolves about the center of the device. The plate and the filament being symmetrically disposed, the applied electric fields, produced by alternating currents supplied to the grids bearing mathematical relation possessed by the expressions described, has the effect of producing a grid control, which func tions in accordance with the amplitudes of the alternating currents impressed upon the said grids, and in accordance with the amplitudes thereof only.

To more fully understand the operation of this embodiment, the function of the entire diagram, Fig. 8 will be described.

15 is the terminal of a communication receiving system; 16 is the terminal apparatus thereof,

being a unit of apparatus suitable for receiving a super-audlo-frequency modulated carrier wave, and either delivering it directly to unit 17, or heterodyning it, it being immaterial to the invention whether the received wave be heterodyned, and the only requirement being that the wave delivered from 17 is a modulated super-audiofrequency carrier wave. The output of 17 is delivered to 18, which is a phase-splitter illustrated conventionally rather than in practical dimensions. The function of the phase-splitter being to divide the carrier wave, such that at 19 and 20 there are delivered two similar concurrent modulation patterns, agreeing with the pattern received in 15, but modulated upon two carrier waves of equal frequency but differing in phase position by 90 electrical degrees. 21 and 22 are loading resistors, which sometimes have practical advantages. The carrier frequency wave-forms of the output circuits 19 and 20 are illustrated by the dotted lines 23 and 24 already fully described.

Output circuit 19 is connected to grids 5 and 7 and output circuit 20 is connected to'grids 4 and 6, Figs. 5 and 8.

The waves 23 and 24 combine as heretfofpre" described, and as shown effect of controlling the in Fig. 6, and have the plate current in accordance with the amplitudes of said waves and in accordance with the amplitudes thereof 'only, through plate battery 25, which is connected in series with a reception translating device 26, which is further connected to the filament circuit at 27, and through a potentiometer controlled battery 28, which may be used if and when desired, and thence to the mid-points of the output secondaries 19 and 20, completing the plate circuit through the filament 1, which may be heated by the battery 29, as is understood by those skilled in the art.

While the embodiment described herein includes an anode in addition to the cathode and multiple grid structure, it is quite obvious to those skilled in the art that if the anode 2 of the Fig. 8 be removed, the grid structure in reality acts as an anode. It is believed unnecessary to describe in detail the operation of Fig. 8 in the absence of anode 2. A closed grid structure, aside from the novelties of structure described herein, has been disclosed in considerable detail in copending application Serial Number 421,790 above referred to.

It is obvious to those skilled in the art that in the prior disclosures employing cylindrical elec trodes, or cylindrically located electrodes, and a rod filament located in the center thereof, a space charge effect is high in such a structure. In the present invention the cathode and the electrodes have been brought much closer together, avoiding this large space factor in the space-charge effect. It will be further appreciated that with such a structure as herein disclosed, the space-charge effect can be reduced to values comparable with those obtained in the common electron tubes employing plane anodes, and plane grids, with filaments parallel thereto. Such electron discharge devices as herein described are sensitive to eccentricity in the filament with respect to the electrodes, which has the effect of producing a varying space-charge effect in the device.

The use of widely spaced hairpin filaments, and similar filament structure, quite obviously produces in effect, a pulsating space-charge effect, having a frequency depending upon the period of revolution of the revolving field. The present invention provides means for eliminating this pulsating space-charge effect.

The applicant does not limit himself to the structure shown in the described embodiment. The limitations of the invention are set forth in the claims hereunder.

I claim:

1. An electron discharge device to be fed byall lobes of a polyphased alternating current line comprising an evacuated vessel containing two electrodes, and a control electrode to be fed by all lobes of said line the distance between said control electrode and one of said two electrodes being different at successive points.

2. An electron discharge device to be fed by all lobes of a polyphased alternating current line comprising an evacuated envelope containing a plurality of electrodes disposed about the diameter of a circle, and a cathode formed into a substantially closed figure and disposed principally in a plane at right angles to the axis of said circle and having a working surface at a mean distance from said electrodes which is less than half the diameter of said circle.

3. An electron discharge device to be fed by all lobes of a polyphased alternating current line comprising a plurality of electrodes disposed radially about a fixed axis to be fed by said lobes, a cathode formed into a substantially closed geometrical figure and lying in plane generally at right angles to said axis.

4. An electron discharge device to be fed by all lobes of a polyphased alternating current line comprising a plurality of electrodes, a cooperating cathode, and supports, said cathode having portions connected to said supports, said portions embodying crossed parts of said cathode.

5. An electron discharge device to be fed by all lobes of a polyphased alternating current line comprising a cathode, an anode cooperating with said cathode, two grids to be fed by said lobes and mounted between said anode and cathode angularly displaced with respect to one another and presenting to the cathode a surface having the contour of a closed non-circular geometric figure.

6. An electron discharge device to be fed by all lobes of a polyphased alternating current line comprising a cathode formed into a closed geometric figure, an anode surrounding said cathode and having an active surface parallel with the cathode, two grids between said anode and cathode angularly displaced with respect to one another and presenting to the cathode a surface having a contour providing greater cathodegrid spacing for one part of said-grid than for another part thereof.

7. An electron discharge device to be'fed by all lobes of a polyphased alternating current line comprising a cathode wire formed into a circle, an anode surrounding said cathode and having an active surface parallel with the cathode wire, two pairs of grids between said anode and cathode presenting to the cathode a surface having a contour of non-circular closed geometric figure, one pair of grids being angularly displaced with respect to the other.

8. An electron discharge device to be fed' by all lobes of a polyphased alternating current line, comprising a cathode formed into a circular figure, an anode surrounding said cathode and having an active surface parallel with the contour of said figure, two pairs of grids between said anode and cathode presenting to the outline of said cathode a surface forming a part of a contour of a non-circular closed geometric figure, one pair of grids being angularly displaced with respect to the other.

9. An electron discharge device to be fed by all lobes of a polyphased alternating current line, comprising two electrodes and a control electrode, one of said two electrodes to be fed by all lobes of said line, the distance between the control electrode and one of said two electrodes being different at successive points, whereby between said two electrodes a distribution of electrostatic field is produced which is sinusoidal with respect to the geometry of the device.

10. An electron discharge device to be fed by all lobes of a polyphased alternating current line and comprising a cathode conductor formed into a circle, an anode surrounding said cathode and having an active surface'parallel with the cathode, two pairs of angularly displaced intermeshed grids, means for mounting said grids between said 

